The present invention relates to a watch and, more particularly, a case for use to the digital wrist watch.
Cheap digital wrist watches have been marketed and become more popular these days. Each of these digital wrist watches has a piece of transparent glass attached to the top of a case, a module housed in the case, and a back lid attached to the bottom side of the case. A band is further attached in a outer wall of the case by means of rods each of which has spring-engaged portions at both ends thereof. The module includes an integrated circuit chip, a source of timing signals or a pulse generator, a display (typically light emitting diodes or a liquid crystal material), and one or more batteries.
In the case of these digital wrist watches, the band is made independently of the case and band-attaching portions must be therefore formed at the outer wall of the case. For the purpose of eliminating this drawback, U.S. Pat. No. 4,229,936, issued Aug. 28, 1980, discloses a case formed integral to the band. The digital wrist watch proposed by this U.S. patent enables the band to be made integral to the case, making it unnecessary to use the rods for attaching the band to the case, and the assembly of the digital wrist watch to be thus made easier because the number of parts used for the watch can be reduced. In the case of this U.S. patent, however, the structure of the case and band is made of soft resin, thereby causing a problem in the structural strength of the watch. More specifically, an auxiliary member or housing, that is, a front case is needed in the case of this U.S. patent to sufficiently protect the module and house the other parts. Therefore, the digital wrist watch cannot be made slim and small in size because of the auxiliary member or housing used.